ok... questions.

On the off chance that I get my car computer to sync up with my Alpine CVA-1005 (I am not sure I'll ever solve this), I get lots of interference on the screen... like lines going through it and the screen looks "busy" with interference. I know it's partially the inverter. I hate the fact that I'm running 12v to an inverter, giving the computer 120v, then the computer is breaking it down to 12v again. Where can I get a good 12v power supply for an ATX computer .. direct wire... that i can plug right into my ATX motherboard? I have seen them.

Second, when the computer boots up, I can hear WHINE coming through the car speakers. I can actually hear the hard drive seeking through the speakers... how to eliminate at least some of this noise?

thanks,
/aac

 

uhhh, I'm not sure where to get a "real" computer power supply that runs off 12VDC, but you can make one out of parts you can purchase at http://www.mpja.com
they sell DC/DC convertors..
you'll need a +12 (wire straight into the car's system, but would be better if you built a 12V voltage regulator so you will always be getting exactly +12V)..
also need +5 and -5 and -12 I think.. plus ground.. but ground is already there.

you can probably build one for around $50.. dunno where to buy a complete one though. good luck there!

As for the whine in the system when your harddrive is spinning- is it just on radio, or when you're listening to CD also?
my home system does that if I have my laptop running near the FM receiver.. it's radio signal interference that the computer itself puts out into the air, and there's nothing you can do about it really..

As for the lines on the screen, that stuff should go away when you get a "correct" power supply.
also maybe try a better 120VAC invertor or plug in a power filter... most of the time those invertors have a very poor quality output unless you get a $$$$ one. you can clean it up somewhat with a power filter, but it may not do enough of the job..

Another work-around would be to buy a computer UPS system, then wire the battery backup from it into your car's battery instead of the UPS's battery.. you may have to do a little fudging to trick the UPS into thinking you're getting 120V power, but I've seen it done..
those UPS have very clean 120VAC output on them, so it may be something to look at also..

hope that gave you some ideas.. good luck!

 

Regarding the speaker whine during boot/hard drive seek, how about some kind of shielding? Unless this PC was specifically designed for an automotive application, I'd bet there's alot of radio noise coming out of the box.

What type of shielding do they use for center-channel speakers in a home theater setup? Maybe you could wrap the PC's system unit in this? Just my $.02.

Jim

 

that wouldn't be possible.. the sheilding they use on speakers involves a large "cap" ot metal crammed over the magnet on the speak, thus killing the magnetic field outisde of it..

these things are heavy and would make things pretty nasty if installed on a computer.
good thought, but it wouldn't work.